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Bugs on Virtual to Virtual Migration from Microsoft to VMware

craig — Sat, 09 Oct 2010 15:22:15 +0000

Recently had found some weird issue while we tried to migrate virtual to virtual from Microsoft Virtual Server 2005 to VMware vSphere 4. The import process done successful by the VMware converter, but we realized the network packets get delay while we performed the continues ping test to the virtual machine. the Ping respond had been delayed more than 1000ms in the LAN environment.
We had verified all the network connectivity, resources allocation from ESX host, which confirmed this was not the problem of the infrastructure we setup. We performed another round of conversion again by powered on the virtual machines from virtual server 2005, before we performed the migration with VMware converter as physical machine mode. The delay ping respond no longer exist after this. We had opened case with VMware tech support and confirm there is not issue on the Virtual Infrastructure we built.

In case anyone of you had the similar experience, I will suggest you to power on the virtual server from Microsoft, and perform the migration process as physical mode.

mgmt-vmware service malfunction

craig — Wed, 08 Jul 2009 07:46:55 +0000

Most of us may had previously experienced a VM which hung in the ESX hosts. Usually we will use the command vmware-cmd utilities to kill or stop the virtual machine. Sometimes we even need to use the vm-support command to force the VM to be stop hardly if vmware-cmd was not worked. Today I found some interesting issue with 1 of the virtual machine. I had executed the instruction to power off from vCenter 4. This virtual machine is running on vsphere 4. After 2 minutes, the virtual machine still showed power on from the vCenter, and I executed again the 2nd command to power off, the system prompted that another process was in progress, and access was denied.

It looked like the virtual machine was hung, and I started to check the virtual machine status from ESX console. I could not find my virtual machine was still running at the time I checked from the command prompt. Some guys may already got panic and restarted the ESX host, but I decided to take a last try and restarted the mgmt-vmware service from /etc/init.d , guess what, it works after that. The vCenter now show the virtual machine had been power off. The inconsistent information of vCenter always cause some issue to the day to day operation. Hope this tip will help the 1 who run to the same situation as I did.

Virtualization on Blade

craig — Sun, 28 Jun 2009 16:50:20 +0000

We see the growth in the market to be more aggressive for consolidation in the data center for both physical and virtual server from time to time. There are plenty of solutions in place allow blade to support virtualization today such as virtual connect from HP, pass through module, infiniband integration Xsigo, Cisco UCS and etc. This had significant resolved the I/O interfaces require per blade to host the virtualization host server. CPU and memory per blade and significant increase with the latest release from all the major server vendors, the CPU, memory and disk I/O are no longer the concerns for virutalization.

But I do want to point out some of weakness on the solutions proposed by the deployment team or vendors that suggest to start with 1 blade chassis to reduce the CAPEX require. To achieve the fully redundancy on the virtualization, we may require NIC teaming, redundant FC connection, redundant ISCSI HBA and etc. Some of the guys may had forgotten about the chassis issues on the blade today. If I would like to run the virtualization hosts or clustering servers on blade, I will not choose to go with only single blade chassis in this case. I will not believe there is 100 % guarantee of no failure on the chassis of the blade. I will definitely suggest to split the blade across to 2 different chassis as minimum to minimize the risk. But of course, we may still have a single point of failure on the SAN which require huge amount of capex investment to keep the production storage to be redundant. Imagine if you run 5 ESX hosts on single blade chassis today, you will easily achieve 15:1 per blade for consolidation, and if you are UNLUCKY enough and your chassis just burn or malfunction for any failure, you will have 75 VMs go down at 1 time and your HA and DRS is not worked at all. You will definitely screw and whack by your business or boss in this case. If we do not have enough capex to start with 2 blade chassis for HA in the virtualization, I will suggest to stick with 1U or 2U rack mount servers to minimize the risk of the business. I am impressed with the blade technology today, but just to start with 1 single chassis for HA and redundancy purpose, will not be my call.

Tips to recover Snapshot problem on VM

craig — Sun, 28 Jun 2009 16:32:15 +0000

You may had experienced the snapshot problem when the snapshot delta virtual disk had become huge which is more than 20GB and is not able to be truncated by removing all the snapshot. Usually the problem occur when the snapshot is no longer available from snapshot manager, but you can see the delta files available from the command prompt or physical folder that contain the Virtual machine images. I experienced the 2nd time now which I am not able to remove the snapshot on a particular virtual machine from snapshot manager and command prompt. The production virtual machine was powered off due to disk full on the specify datastore. This virtual machine contain a previous snapshot which taken 2 weeks before and yet to be truncated. The delta disk had grown up to >20 GB and fully fill up the available space within the data store.

In order to recover the virtual machine, I had to remove all the snapshots on the virtual machine, but the process hang up after 3 to 4 times I tried. You may able to perform this with command and if you are lucky enough, you should able to remove the snapshot by using command. Alternatively, you can also clone a new virtual disk image contain the delta file changes to a whole new virtual disk by using vmkfstools command. This will require quite some times for you to recover the situation mostly the business will not able to wait and it is no guarantee that the recovery will fully work as we expected.

For my case, the quickest way to recover this is to clone the entire virtual machine to a new datastore that have the disk space you require and power it up immediate after the clone. We double checked the entire virtual machines mount point and services, everything require and last file transaction is available without any issue and back to production. Now I will have my sweet time to slowly investigate the failure to remove snapshots on the virtual machines. Well, is not necessary the method I am using here is the best, but I would like to share my personal experience in the critical production time, you may wanna consider the best option to recover the production virtual machine as soon as possible.

Improve Utilization on ESX Hosts

craig — Sun, 17 May 2009 03:20:02 +0000

As virtualization does help us to consolidate virtual machines into physical servers, we are always looking into a better consolidation ratio and hardware utilization. We may not want to achieve this by hitting to performance issue on the virtual infrastructure. Here is 1 of the way you may consider to improve the utilization on your ESX host.

As my environment, the virtual infrastructure are supporting our global business in Asia Pacific, EMEA and NA time zone. When I tracked back the performance history and found the busy hour for most of the machines will be different. Due to the time zone different, I notice that the hardware utilization on the ESX host are always remain 40 to 50 % all the time.

With the data record on hand, I decided to re-allocate the virtual machines in my virtual machine with VMotion to improve utilization on our virtual infrastructure. I had balanced allocated the Asia Pacific machine mix with Europe and North America servers on every esx host. In this case, we had able to consolidate more servers into every ESX host, and users do not experience slow performance after the changes been made. As now, the maximum CPU utilization on the ESX host always remain at 70% at the peak hour which is due to the time zone crossing from Asia pacific with EMEA hour. This peak utilization will not stay longer than 4 hours and it will back to normal once Asia Pacific office hour is end.

This trick may not work for everyone, but if your environment do similar with what happen here, this should work. As today, I do not utilize the resource pool after the virtual machines re-allocation I did. Of course, you may need to assign the resources carefully to every virtual machines.

Offline VM Migration auto convert RDM to VMDK format

craig — Thu, 09 Apr 2009 17:06:23 +0000

Due to some reconfiguration work we performed on our Virtual Infrastructure, we had required to relocate some of the VM to a different datastore. These VMs which required to be moved had been attached with Raw Device Mapping (RDM). Previously I thought the offline storage migration will not move the RDM over to the datastore as RDM is referring to the raw device from the SAN storage.Actually I was planned to convert the RDM to VMDK which I planned to manual transfer the files I need from RDM to the new virtual disk I created.

In a test yesterday, we found that a offline VM migration will auto convert the RDM which attach to the virtual machine to the VMDK format when I selected the data store to be moved in offline mode. This was really surprise myself and simplify my work actually, as I do not require some manual file transfer from the RDM to the new virtual disk.

Windows 7 on vSphere

craig — Mon, 23 Mar 2009 08:35:14 +0000

Previously I had my windows 7 running on ESX 3.5, Workstation and VMware Server 2.0, and now I have my windows 7 on VMware vSphere, the next generation of ESX server from VMware. Notice that the operating system option will not provide windows 7 for your selection, which I believe VMware will include this on the final release of vSphere when windows 7 become officially launch to public. Anyway, you can still install it on your ESX or vSphere by choosing Windows Vista as an option.

A success installation of windows 7 on vSphere. I had able to installed the VMtools properly on the Virtual Machine.

Here is the weird thing happen, which the Operating system information tab had shown as Windows NT 4.0. Anyway, this is not a major concern for myself, as long as it run as I need. The VM only support up to 2 vcpu at this moment, although I am running windows 7 64 bits in my test.

Virtual CPU Increase on Demand in vSphere

craig — Fri, 20 Mar 2009 07:41:56 +0000

vSphere will match with the competitor hypervisor to deliver up to 8 vCpu per VM. This will increase the CPU resources to VM guest which may require more than 4 vcpu previously. At the same time, it also provide the flexibility to support multiple vcpu from 1 to 8.

Configure 5 Vcpu for the VM

Task Manager in Windows show 5 cores are active

Summary Tab shows 5 vcpu had been assigned. In physical Server environment, we will usually start with 1 cpu, 2 cpus, 4 cpus, 8 cpus and etc. This features from vmware vSphere is really helpful and allow us to control and prevent over provision to the virtual Machine

Memory Hot Add for Virtual Machine

jlchannel — Fri, 20 Mar 2009 03:39:55 +0000

The next version of ESX vSphere or ESX 4 new features – Memory “Hot Add” for virtual machine is not a secret anymore. The most important is Microsoft announced the drop of hot-add support from its roadmap, postponed to an unannounced date, reported by Virtualization.Info which is totally not make sense and it’s confirmed worked on next version of ESX/vCenter.

I would like to share how to configure memory “hot add” for Windows 2003 virtual machine.

Please make sure the virtual machine is power off before proceed and this is one time setup.

Right click on virtual machine
Click Edit Settings
Click Options
Select “Enable memory hot add for this virtual machine” under Memory/CPU Hotplug.
Click OK

Testing time! Power on your virtual machine and increase your memory size on the fly now.

Note: You can increase the memory on the fly but NOT decrease the memory during virtual machine is power on.

Enjoy!

Maximum Configuration allow in Virtual Center ESX VM

craig — Sat, 28 Feb 2009 05:15:26 +0000

As many of the users are trying to search around the latest details of maximum configuration supported in Virtual Center, ESX and VM, you can refer to the latest version of the documentation released by VMware here.

Updated: Maximum Configuration Supported in ESX 3.5 and VC 2.5

This information is always important and helpful for you to plan your environment.